Hundreds of protesters have blocked store entrances and clogged traffic in Chicago's downtown shopping district, to protest the shooting death of a black teenager by a white policeman last year and the city's handling of the case.

Politician and civil rights activist Jesse Jackson led the the march, which is taking place on the day after Thanksgiving, or "Black Friday," traditionally one of the busiest shopping days of the year in the United States.

Police officers formed a barrier of sorts between the protesters and stores and helped shoppers get through the doors. But protesters succeeded in blocking the entrances to several large stores.

The demonstration comes three days after police, acting under a court order, released footage from a dashboard-mounted video camera that captured the October 20, 2014 shooting death of 17-year-old Laquan McDonald. McDonald was shot 16 times, with several bullets strike him while he was already on the ground.

On Tuesday, shortly before the video was released, Van Dyke was arrested and charged with first-degree murder. He has been fired from the police department.

Police have said that, at the time of the shooting, McDonald was behaving erratically, had drugs in his system, and refused police commands to drop a knife he was holding. Van Dyke's lawyer says the officer felt his life was in danger.

Meanwhile, Chicago police say they have made an arrest in the shooting death of a 9-year-old boy, whose alleged gang-related slaying has sparked outrage in the city.

In a news conference Friday, police Superintendent Garry McCarthy announced the arrest of 27-year-old Corey Morgan in the "unfathomable, targeted execution" of Tyshawn Lee. He said Morgan was charged with first-degree murder.

McCarthy said another person believed involved in the case is in custody on an unrelated charge, and a third is wanted in connection with what the superintendent called a "heinous crime."

Chicago police say Lee was lured into an alley and killed because of his family's gang involvement.

Chicago's South Side, where Lee was gunned down, has seen a drastic rise in homicides in recent months. In the neighborhood where Lee was killed, gangs battle over turf to sell drugs.